Transistors, such as metal oxide semiconductor field-effect transistors (MOSFETs), are the core building block of the vast majority of semiconductor devices. Some semiconductor devices, such as high performance processor devices, can include millions of transistors. For such devices, decreasing transistors size, and thus increasing transistor density, has traditionally been a high priority in the semiconductor manufacturing industry. Increasing density necessarily involves reducing the area between neighboring devices, which in turn, requires reliable isolation between devices to prevent leakage currents, parasitic capacitances, and other undesirable electrical effects that may degrade performance and/or reduce yield.